SEISMICKÝ SEMINÁŘ
/ SEMINAR ON SEISMOLOGY

Seminář o aktuálních problémech v oblasti seismického výzkumu Země.

Letní semestr / Summer term 2016/17

3. 3. J. Michálek (Univerzita v Bergenu)
O seismické aktivitě oblasti Nordland (Norsko); aneb co jsem tam ty dva roky vlastně dělal
10. 3. T. Fischer (PřF UK)
Efektivní pokles napětí seismických shluků
17. 3. M. Wcislo (MFF UK a ÚSMH AV ČR), L. Eisner (ÚSMH AV ČR)
Influence of wastewater injection on seismic attenuation and Vp/Vs ratio − an example of Costa Molina 2 well (Agri Valley, Italy)
24. 3. L. Vecsey (GFÚ AV ČR)
Kontrola kvality seismických dat − co vše v datech nevidíme (a co vidět nechceme)
31. 3. F. Kostka a F. Gallovič (MFF UK)
Inverze seismogramů na dynamický model konečného zdroje, aplikace na zemětřesení Amatrice, Itálie 2016 (pracovní seminář)
7. 4.  
 
14. 4. státní svátek
 
21. 4. M. Halló a F. Gallovič (MFF UK)
Zemětřesná sekvence M7 Kumamoto (2016) − momentové tenzory, jejich neurčitosti a složitá tektonika oblasti
28. 4. EGU Vídeň
 
5. 5. J. Málek (ÚSMH AV ČR), J. Brokešová a O. Novotný (MFF UK)
Jak jsme určili strukturu kůry a nejsvrchnějšího pláště pod poloostrovem Reykjanes na jihozápadním Islandu
12. 5. E. Sokos (University of Patras)
Hellenic Unified Seismic Network − status and perspectives
19. 5. Ľ. Valentová a F. Gallovič (MFF UK), P. Maierová (ČGS)
Trojrozměrná tomografie Českého masivu ze seismického šumu
24. 5.
13:10 
John R. Evans (U.S. Geological Survey, Santa Cruz, California)
Epistemic uncertainty and other pitfalls of seismic tomography
In the view of this old teleseismic tomographer, many interpretations of tomographic results go far beyond what can be inferred with any real confidence. Some of the issues are inadequate analysis of aleatoric uncertainty, the uncertainties one normally considers (e.g., via the checkerboard test). Happily, this interpretive weakness is relatively easy to correct by more nuanced and complete analyses of this type of uncertainty.
However, there is another class of uncertainty, epistemic, that is almost always ignored in seismic tomography (and until recently, in most other fields). Epistemic uncertainties refer to not being certain that one is using apropos methods with the apropos data and apropos caution. These uncertainties are very difficult to quantify, but their existence should have profound effects on the limits of one’s confidence in making interpretations of tomographic results.
This talk attempts to alert tomographers and all those, like geologists, who use the interpretations made by tomographers, to these issues and caution that over-interpretations are abundant in the literature and need to be reduced in future work.
29. 5.
13:10 
John R. Evans (U.S. Geological Survey, Santa Cruz, California)
Portable sensors for rotational seismology and engineering
The wider use of rotational motions in both seismology and earthquake (i.e., structural) engineering have been awaiting the wider availability of apropos sensors. Apropos rotational sensors would be those with sufficiently high rotational sensitivity, sufficiently low translational sensitivity (difficult), costs on par with translational seismometers, and with operational characteristics attuned to both portable and observatory applications (low power usage, commonly with no mains power), insensitivity to EMI, IP-67 resistance to water and dust, and so forth. Even in the approximately 15 years now ending, which lacked commercial instruments of this description, much theoretical work and available instruments (developmental sensors, some inertial-navigation sensors, and a few costly but magnificent instruments like the G-ring and ROMY) have yielded enough techniques and results for practical uses and demonstrations of the efficacy of rotational data. Johana Brokešová and Jiří Málek’s development and application of the Rotaphone have made them one of the primary contributors to the development of this new field. For broadband data, the LMU-Wettzell collaboration (G-ring and ROMY) has been a font of new methods and analyses of rotational data. Further, there are many other individuals and groups working along similar lines. All these groups are part of IWGoRS (International Working Group on Rotational Seismology), which includes members from Germany, the Czech Republic, Poland, Taiwan, New Zealand, the U.S., and other countries. With this strong background and emerging instrumentation, the field is in renaissance and that rotational motions and methods are poised to become accepted and in routine use, just as has been translational motions have been for a century. In this talk I review existing and nascent instruments, which are the requisite precursors to this renaissance reaching a wider audience.
21. 6.
14:00 
Juraci de Carvalho (University of Brasilia)
Status and perspectives of seismic investigations in Brazil

Seminář začíná vždy v pátek od 14:00 v Troji.